How it works :  the illustrated encyclopedia of science and technology / 
Edited by Donald Clarke...[et al.]. 
 - New york :  Marshall Cavendish,  c 1978. 
 - Vols. :  ill. ;  28 cm. 
<br/><br/>V. 20- Welding-Zworykin ; 
<br/><br/>42  42 
<br/><br/><label>ISBN: </label>0-85685-522-7 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Dictionaries & encyclopedias<br/>Science and technology
<br/><br/><label>Dewey Class. No.: </label>503 / I6